Known in the art is a method for placing several circular saw blades axially transferrably on a common shaft (U.S. Pat. No. 3,630,244). This arrangement has a drawback in that the gap between the adjacent circular saw blades does permit the placement of edge shaping cutters to correct width for the trimming of the boards, but instead, the milling of the edge must be performed as a separate workphase.
Also known in the art is an arrangement in which the edging of the log prior sawing is unnecessary and which makes the axial adjustment of spacing between the saw blades possible. One such implementation is disclosed in FI patent application 881402. The system described in the application comprises a circular saw blade assembly which has two circular saw blades on a spindle and the spindle hubs are further designed to act as cutters, whereby the cutter attached to the inner circular saw blade is formed into a cage supporting by its end side an inner circular saw blade, and the inner cutter supporting an outer circular saw blade by its end side is located axially transferrable inside the cage-like cutter and extends through the center hole of the inner circular saw blade.
Such an axially adjustable circular saw blade assembly has only two circular saw blades, whereby only a wane and a slab can be cut from a log. The construction of the circular saw blade assembly is complicated, thereby leading to high costs. One of the cutters has constantly a maximum width, which causes wasteful use of log material, and correspondingly, to unnecessary growth of expenses. In addition, the diametrical difference of the cutters is small, which limits their useful operating range.